In the current long term evolution (LTE for short) system, when a user equipment (UE) performs packet switched (PS for short) services, via an eNodeB (eNB for short) of an evolved Universal Mobile Telecommunications System territorial radio access network (E-UTRAN for short) system device, a mobility management entity (MME for short) and a serving gateway (S-GW for short), a data plane transmission tunnel with a packet data network gateway (P-GW for short) and a policy and charging rules function (PCRF for short) device and so on, is established through a control signaling.
In other words, the UE accesses a core network via an attachment process at first, and during the process of accessing the core network, the MME may initiate, based on an access point (APN for short), a packet data network (PDN for short) connection establishing process, and then establish a data plane transmission tunnel, i.e., a bearer which carries a data flow of the user equipment, for the data transmission of the user equipment.
However, due to the limited capacity of each cell deployed in a wireless network, congestion may be resulted from excessive accessing of the user equipments, for example, a cell includes a lot of user terminals such as (UE1, UE2, UE3 . . . UEN), then each UE uses a plurality of bearers via an eNB, which thereby easily leads to the congestion of the cell.
At present, there are only two following ways in which a gateway device at a core network side learns the congestion state of a cell, one way is that: when the cell is congested, an access network device such as an eNB sends a congestion notifying message to a mobility management entity (such as a MME or a SGSN), after the gateway device at the core network side or a policy and charging control (PCC for short) device learns that the cell is congested, an operation of deactivating some bearers or separating some users to relieve the congestion state may be initiated; the other way is that: when the cell is congested, the eNB sends a notifying message to the gateway device at the core network side via a data plane tunnel of a bearer, such as by setting a congestion state instruction in a header of an uplink data packet in the data plane tunnel, so that the gateway device senses the cell congestion, and further notifies the core network to initiate an operation of modifying quality of service (QoS for short) of the bearer or an application service flow, such as but not limited to decreasing a maximum bit rate (MBR for short) and a guaranteed bit rate (GBR for short), which serves to relieve the congestion state.
However, a drawback according to the first aforementioned way is that there is no similar processing procedure in the present 3GPP protocol, if such a process is added, there may be great influences on the existing protocol; a drawback of the second way is that a congestion state indication is added to the uplink data packet of each bearer, so that each gateway device may receive lots of uplink data packets including the reported congestion state, which further aggravates the congestion state and may increase the processing complexity of the gateway device such as a P-GW and decrease the processing performance of the gateway device.